drivers/staging/iio/accel/adis16240_ring.c

   1 #include <linux/interrupt.h>
   2 #include <linux/irq.h>
   3 #include <linux/gpio.h>
   4 #include <linux/workqueue.h>
   5 #include <linux/mutex.h>
   6 #include <linux/device.h>
   7 #include <linux/kernel.h>
   8 #include <linux/spi/spi.h>
   9 #include <linux/slab.h>
  10 #include <linux/sysfs.h>
  11 #include <linux/list.h>
  12
  13 #include "../iio.h"
  14 #include "../sysfs.h"
  15 #include "../ring_sw.h"
  16 #include "accel.h"
  17 #include "../trigger.h"
  18 #include "adis16240.h"
  19
  20 static IIO_SCAN_EL_C(supply, ADIS16240_SCAN_SUPPLY, IIO_UNSIGNED(10),
  21                 ADIS16240_SUPPLY_OUT, NULL);
  22 static IIO_SCAN_EL_C(accel_x, ADIS16240_SCAN_ACC_X, IIO_SIGNED(10),
  23                 ADIS16240_XACCL_OUT, NULL);
  24 static IIO_SCAN_EL_C(accel_y, ADIS16240_SCAN_ACC_Y, IIO_SIGNED(10),
  25                 ADIS16240_YACCL_OUT, NULL);
  26 static IIO_SCAN_EL_C(accel_z, ADIS16240_SCAN_ACC_Z, IIO_SIGNED(10),
  27                 ADIS16240_ZACCL_OUT, NULL);
  28 static IIO_SCAN_EL_C(aux_adc, ADIS16240_SCAN_AUX_ADC, IIO_UNSIGNED(10),
  29                 ADIS16240_AUX_ADC, NULL);
  30 static IIO_SCAN_EL_C(temp, ADIS16240_SCAN_TEMP, IIO_UNSIGNED(10),
  31                 ADIS16240_TEMP_OUT, NULL);
  32
  33 static IIO_SCAN_EL_TIMESTAMP(6);
  34
  35 static struct attribute *adis16240_scan_el_attrs[] = {
  36         &iio_scan_el_supply.dev_attr.attr,
  37         &iio_scan_el_accel_x.dev_attr.attr,
  38         &iio_scan_el_accel_y.dev_attr.attr,
  39         &iio_scan_el_accel_z.dev_attr.attr,
  40         &iio_scan_el_aux_adc.dev_attr.attr,
  41         &iio_scan_el_temp.dev_attr.attr,
  42         &iio_scan_el_timestamp.dev_attr.attr,
  43         NULL,
  44 };
  45
  46 static struct attribute_group adis16240_scan_el_group = {
  47         .attrs = adis16240_scan_el_attrs,
  48         .name = "scan_elements",
  49 };
  50
  51 /**
  52  * adis16240_poll_func_th() top half interrupt handler called by trigger
  53  * @private_data:       iio_dev
  54  **/
  55 static void adis16240_poll_func_th(struct iio_dev *indio_dev, s64 time)
  56 {
  57         struct adis16240_state *st = iio_dev_get_devdata(indio_dev);
  58         st->last_timestamp = time;
  59         schedule_work(&st->work_trigger_to_ring);
  60 }
  61
  62 /**
  63  * adis16240_read_ring_data() read data registers which will be placed into ring
  64  * @dev: device associated with child of actual device (iio_dev or iio_trig)
  65  * @rx: somewhere to pass back the value read
  66  **/
  67 static int adis16240_read_ring_data(struct device *dev, u8 *rx)
  68 {
  69         struct spi_message msg;
  70         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  71         struct adis16240_state *st = iio_dev_get_devdata(indio_dev);
  72         struct spi_transfer xfers[ADIS16240_OUTPUTS + 1];
  73         int ret;
  74         int i;
  75
  76         mutex_lock(&st->buf_lock);
  77
  78         spi_message_init(&msg);
  79
  80         memset(xfers, 0, sizeof(xfers));
  81         for (i = 0; i <= ADIS16240_OUTPUTS; i++) {
  82                 xfers[i].bits_per_word = 8;
  83                 xfers[i].cs_change = 1;
  84                 xfers[i].len = 2;
  85                 xfers[i].delay_usecs = 30;
  86                 xfers[i].tx_buf = st->tx + 2 * i;
  87                 st->tx[2 * i]
  88                         = ADIS16240_READ_REG(ADIS16240_SUPPLY_OUT + 2 * i);
  89                 st->tx[2 * i + 1] = 0;
  90                 if (i >= 1)
  91                         xfers[i].rx_buf = rx + 2 * (i - 1);
  92                 spi_message_add_tail(&xfers[i], &msg);
  93         }
  94
  95         ret = spi_sync(st->us, &msg);
  96         if (ret)
  97                 dev_err(&st->us->dev, "problem when burst reading");
  98
  99         mutex_unlock(&st->buf_lock);
 100
 101         return ret;
 102 }
 103
 104
 105 static void adis16240_trigger_bh_to_ring(struct work_struct *work_s)
 106 {
 107         struct adis16240_state *st
 108                 = container_of(work_s, struct adis16240_state,
 109                                 work_trigger_to_ring);
 110
 111         int i = 0;
 112         s16 *data;
 113         size_t datasize = st->indio_dev
 114                 ->ring->access.get_bpd(st->indio_dev->ring);
 115
 116         data = kmalloc(datasize , GFP_KERNEL);
 117         if (data == NULL) {
 118                 dev_err(&st->us->dev, "memory alloc failed in ring bh");
 119                 return;
 120         }
 121
 122         if (st->indio_dev->scan_count)
 123                 if (adis16240_read_ring_data(&st->indio_dev->dev, st->rx) >= 0)
 124                         for (; i < st->indio_dev->scan_count; i++)
 125                                 data[i] = be16_to_cpup(
 126                                         (__be16 *)&(st->rx[i*2]));
 127
 128         /* Guaranteed to be aligned with 8 byte boundary */
 129         if (st->indio_dev->scan_timestamp)
 130                 *((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 131
 132         st->indio_dev->ring->access.store_to(st->indio_dev->ring,
 133                         (u8 *)data,
 134                         st->last_timestamp);
 135
 136         iio_trigger_notify_done(st->indio_dev->trig);
 137         kfree(data);
 138
 139         return;
 140 }
 141
 142 void adis16240_unconfigure_ring(struct iio_dev *indio_dev)
 143 {
 144         kfree(indio_dev->pollfunc);
 145         iio_sw_rb_free(indio_dev->ring);
 146 }
 147
 148 int adis16240_configure_ring(struct iio_dev *indio_dev)
 149 {
 150         int ret = 0;
 151         struct adis16240_state *st = indio_dev->dev_data;
 152         struct iio_ring_buffer *ring;
 153         INIT_WORK(&st->work_trigger_to_ring, adis16240_trigger_bh_to_ring);
 154         /* Set default scan mode */
 155
 156         iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
 157         iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
 158         iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
 159         iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
 160         iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
 161         iio_scan_mask_set(indio_dev, iio_scan_el_aux_adc.number);
 162         indio_dev->scan_timestamp = true;
 163
 164         indio_dev->scan_el_attrs = &adis16240_scan_el_group;
 165
 166         ring = iio_sw_rb_allocate(indio_dev);
 167         if (!ring) {
 168                 ret = -ENOMEM;
 169                 return ret;
 170         }
 171         indio_dev->ring = ring;
 172         /* Effectively select the ring buffer implementation */
 173         iio_ring_sw_register_funcs(&ring->access);
 174         ring->bpe = 2;
 175         ring->preenable = &iio_sw_ring_preenable;
 176         ring->postenable = &iio_triggered_ring_postenable;
 177         ring->predisable = &iio_triggered_ring_predisable;
 178         ring->owner = THIS_MODULE;
 179
 180         ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16240_poll_func_th);
 181         if (ret)
 182                 goto error_iio_sw_rb_free;
 183
 184         indio_dev->modes |= INDIO_RING_TRIGGERED;
 185         return 0;
 186
 187 error_iio_sw_rb_free:
 188         iio_sw_rb_free(indio_dev->ring);
 189         return ret;
 190 }
 191